1.C/EBPβ/AEP Signaling Drives Alzheimer's Disease Pathogenesis.
Jing XIONG ; Zhentao ZHANG ; Keqiang YE
Neuroscience Bulletin 2023;39(7):1173-1185
Alzheimer's disease (AD) is the most common type of dementia. Almost two-thirds of patients with AD are female. The reason for the higher susceptibility to AD onset in women is unclear. However, hormone changes during the menopausal transition are known to be associated with AD. Most recently, we reported that follicle-stimulating hormone (FSH) promotes AD pathology and enhances cognitive dysfunctions via activating the CCAAT-enhancer-binding protein (C/EBPβ)/asparagine endopeptidase (AEP) pathway. This review summarizes our current understanding of the crucial role of the C/EBPβ/AEP pathway in driving AD pathogenesis by cleaving multiple critical AD players, including APP and Tau, explaining the roles and the mechanisms of FSH in increasing the susceptibility to AD in postmenopausal females. The FSH-C/EBPβ/AEP pathway may serve as a novel therapeutic target for the treatment of AD.
Female
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Humans
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Male
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Alzheimer Disease/pathology*
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CCAAT-Enhancer-Binding Protein-beta/metabolism*
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Cognitive Dysfunction/metabolism*
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Signal Transduction
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Follicle Stimulating Hormone
2.Expression of CCAAT/enhancer binding protein beta in human gastric carcinoma and its clinical significance.
Yun-xia DU ; Lian-hai ZHANG ; Xiao-hong WANG ; Xiao-fang XING ; Xiao-jing CHENG ; Hong DU ; Ying HU ; Ying-ai LI ; Yu-bing ZHU ; Yong-ning JIA ; Yi LIN ; Jia-fu JI
Chinese Journal of Gastrointestinal Surgery 2013;16(2):179-182
OBJECTIVETo explore the expression of CCAAT/enhancer binding protein beta (CEBPB) in gastric carcinoma tissues and its association with clinicopathological features and prognosis.
METHODSCEBPB protein expression level was detected by immunohistochemistry method in resected gastric carcinomas and adjacent gastric mucosa tissues (n=81), and its association with clinicopathological features and prognosis was analyzed.
RESULTSThe immunohistochemical staining of CEBPB was predominantly in the nucleus with some cytoplasmic staining. As a result, 16% (13/81) of the gastric carcinomas were stained positively, whereas there was hardly positive expression in adjacent gastric mucosa tissues. There was a significant association between the expression of CEBPB and distant metastasis on univariate analysis (P<0.05). The median survival time in patients with positive CEBPB expression was significantly lower than those with negative CEBPB expression (19.4 months vs. 45.2 months, P=0.024). Multivariable analysis showed that CEBPB was independently associated with prognosis (HR=2.544, 95%CI:1.154-5.610, P=0.021).
CONCLUSIONUp-regulation of CEBPB suggests poor prognosis in patients with gastric cancer.
Adult ; Aged ; Aged, 80 and over ; CCAAT-Enhancer-Binding Protein-beta ; metabolism ; Female ; Gastric Mucosa ; metabolism ; pathology ; Humans ; Male ; Middle Aged ; Prognosis ; Stomach Neoplasms ; metabolism ; pathology
3.L-4F Inhibits Oxidized Low-density Lipoprotein-induced Inflammatory Adipokine Secretion via Cyclic AMP/Protein Kinase A-CCAAT/Enhancer Binding Protein β Signaling Pathway in 3T3-L1 Adipocytes.
Xiang-Zhu XIE ; Xin HUANG ; Shui-Ping ZHAO ; Bi-Lian YU ; Qiao-Qing ZHONG ; Jian CAO
Chinese Medical Journal 2016;129(9):1108-1112
BACKGROUNDAdipocytes behave like a rich source of pro-inflammatory cytokines including monocyte chemoattractant protein-1 (MCP-1). Oxidized low-density lipoprotein (oxLDL) participates in the local chronic inflammatory response, and high-density lipoprotein could counterbalance the proinflammatory function of oxLDL, but the underlying mechanism is not completely understood. This study aimed to evaluate the effect of apolipoprotein A-I mimetic peptide L-4F on the secretion and expression of MCP-1 in fully differentiated 3T3-L1 adipocytes induced by oxLDL and to elucidate the possible mechanisms.
METHODSFully differentiated 3T3-L1 adipocytes were incubated in the medium containing various concentration of L-4F (0-50 μg/ml) with oxLDL (50 μg/ml) stimulated, with/without protein kinase A (PKA) inhibitor H-89 (10 μmol/L) preincubated. The concentrations of MCP-1 in the supernatant, the mRNA expression of MCP-1, the levels of CCAAT/enhancer binding protein α (C/EBPα), and CCAAT/enhancer binding protein β (C/EBPβ) were evaluated. The monocyte chemotaxis assay was performed by micropore filter method using a modified Boyden chamber.
RESULTSOxLDL stimulation induced a significant increase of MCP-1 expression and secretion in 3T3-L1 adipocytes, which were inhibited by L-4F preincubation in a dose-dependent manner. PKA inhibitor H-89 markedly reduced the oxLDL-induced MCP-1 expression, but no further decrease was observed when H-89 was used in combination with L-4F (50 μg/ml) (P > 0.05). OxLDL stimulation showed no significant effect on C/EBPα protein level but increased C/EBPβ protein level in a time-dependent manner. H-89 and L-4F both attenuated C/EBPβ protein level in oxLDL-induced 3T3-L1 adipocytes.
CONCLUSIONSOxLDL induces C/EBPβ protein synthesis in a time-dependent manner and enhances MCP-1 secretion and expression in 3T3-L1 adipocytes. L-4F dose-dependently counterbalances the pro-inflammatory effect of oxLDL, and cyclic AMP/PKA-C/EBPβ signaling pathway may participate in it.
3T3-L1 Cells ; Animals ; CCAAT-Enhancer-Binding Protein-beta ; analysis ; physiology ; Chemokine CCL2 ; genetics ; secretion ; Cyclic AMP ; physiology ; Cyclic AMP-Dependent Protein Kinases ; physiology ; Humans ; Lipoproteins, LDL ; antagonists & inhibitors ; pharmacology ; Mice ; Peptides ; pharmacology ; Signal Transduction ; physiology
4.Cres (cystatin-related epididymal spermatogenic) gene regulation and function.
National Journal of Andrology 2002;8(5):313-318
The CRES (cystatin-related epididymal spermatogenic) protein defines a new subgroup in the family 2 cystatins of the cystatin superfamily of cysteine protease inhibitors. However, unlike the ubiquitous expression of cystatin C, the Cres gene is preferentialy expressed in postmeiotic germ cells, the proximal caput epididymidis, and anterior pituitary gonadotrophs. Furthermore, CRES protein lacks two of the three consensus sites necessary for the cystatin inhibition of C1 cysteine proteases. Therefore, CRES may perform unique and tissue-specific functions in the reproductive and neuroendocrine systems. In the present review, we describe our studies on: 1. the Cres gene promoter and the transcriptional regulatory protein and their associated DNA binding sites that may be important for tissue-specific expression; and 2. the biochemical function of CRES protein. In brief, Northern blot, gel shift analyses, and transient transfection assays demonstrated that the C/EBP beta (CCAAT/enhancer binding protein) transcription factor is the predominant C/EBP family member expressed in the epididymis and gonadotroph cells and is necessary for high levels of Cres expression in these two tissues. In other studies, analyses of transgenic mice expressing a CAT reporter gene driven by 1.6 kb of Cres promoter revealed CAT mRNA and protein only in the germ cells. These studies suggest that the 1.6 kb of Cres 5' flanking sequence contains the required DNA elements for expression in the testis, but lacks the elements to correctly target expression of the reporter gene in the epididymis. Alternatively, repressor elements may be present. Finally, in vitro protease assays were performed to determine if CRES functions as a protease inhibitor. In contrast to cystain C, CRES did not inhibit the C1 cysteine protease papain but rather inhibited at nanomolar concentrations the serine protease PC2, a prohormone processing enzyme. Therefore, CRES is a new cross-class inhibitor that may regulate PC2 of PC2-like proteases and suggests a role for CRES in the regulation of prohormone and proprotein processing.
Amino Acid Sequence
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Animals
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CCAAT-Enhancer-Binding Protein-beta
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biosynthesis
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Cystatins
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classification
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genetics
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physiology
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Epididymis
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metabolism
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Gene Expression Regulation
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Humans
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Male
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Mice
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Mice, Transgenic
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Promoter Regions, Genetic
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genetics
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Sequence Homology, Amino Acid
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Spermatogenesis
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physiology
5.Tackling the tumor microenvironment: what challenge does it pose to anticancer therapies?
Fei CHEN ; Xinyi QI ; Min QIAN ; Yue DAI ; Yu SUN
Protein & Cell 2014;5(11):816-826
Cancer is a highly aggressive and devastating disease, and impediments to a cure arise not just from cancer itself. Targeted therapies are difficult to achieve since the majority of cancers are more intricate than ever imagined. Mainstream methodologies including chemotherapy and radiotherapy as routine clinical regimens frequently fail, eventually leading to pathologies that are refractory and incurable. One major cause is the gradual to rapid repopulation of surviving cancer cells during intervals of multiple-dose administration. Novel stress-responsive molecular pathways are increasingly unmasked and show promise as emerging targets for advanced strategies that aim at both de novo and acquired resistance. We highlight recent data reporting that treatments particularly those genotoxic can induce highly conserved damage responses in non-cancerous constituents of the tumor microenvironment (TMEN). Master regulators, including but not limited to NF-kB and C/EBP-β, are implicated and their signal cascades culminate in a robust, chronic and genome-wide secretory program, forming an activated TMEN that releases a myriad of soluble factors. The damage-elicited but essentially off target and cell non-autonomous secretory phenotype of host stroma causes adverse consequences, among which is acquired resistance of cancer cells. Harnessing signals arising from the TMEN, a pathophysiological niche frequently damaged by medical interventions, has the potential to promote overall efficacy and improve clinical outcomes provided that appropriate actions are ingeniously integrated into contemporary therapies. Thereby, anticancer regimens should be well tuned to establish an innovative clinical avenue, and such advancement will allow future oncological treatments to be more specific, accurate, thorough and personalized.
Antineoplastic Agents
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therapeutic use
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CCAAT-Enhancer-Binding Protein-beta
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metabolism
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Humans
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Models, Biological
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Molecular Targeted Therapy
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methods
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trends
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NF-kappa B
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metabolism
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Neoplasms
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drug therapy
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metabolism
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Precision Medicine
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methods
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trends
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Signal Transduction
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drug effects
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Tumor Microenvironment
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drug effects
6.Studies on the genetic pathogenesis of myasthenia gravis caused by CTLA-4 gene polymorphism.
Hai-ting MAO ; Xiong-biao WANG ; Ling ZHANG ; Hong-tao GU
Chinese Journal of Medical Genetics 2004;21(6):574-578
OBJECTIVETo study the genetic pathogenesis of myasthenia gravis (MG) caused by cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene polymorphisms and regulation function of transcription factor.
METHODSELISA assay was used to determine the expression level of serum sCTLA-4 in MG. Four single nucleotide polymorphisms (SNPs) of CTLA-4 at exon 1 +49, promoter -318, -1661, -1772 were analyzed by restriction fragment length polymorphism (RFLP). Transcription factor nuclear factor 1(NF-1) and c/EBPbeta binding site were confirmed by chromatin immunoprecipitation(CHIP) assay.
RESULTSIt was found that the frequencies of the GG+49 genotype and G+49 allele are higher in MG patients with thymoma than those in patients of thymic hyperplasia and normal thymus subgroups. T/C-318 is not correlated with MG. The frequency of CT-1772 genotype is significantly higher in MG patients, especially in MG patients with thymoma, when compared with that in healthy controls. Meanwhile, the frequency of the G-1661 allele and GG-1661 genotype is lower in MG patients. Linkage disequilibrium (LD) between each SNPs in promoter -1772, -1661, -318 and coding sequence 1 (CDS 1) +49 is apparent. sCTLA-4 levels in patients' sera are correlated with the haplotype and genotype. T/C-1772 and A/G-1661 SNPs change the sequence of transcription factor NF-1 and c/EBPbeta binding sites. DNA variants lose site-specific binding activity of transcription factor regulated by lectin ConA and PHA.
CONCLUSIONThere are strong positive linkages among four SNPs. C/T-1772 and A/G-1661 polymorphisms can result in inefficient transcription of CTLA-4 gene. T>C-1772 mutation also affects gene splicing. These SNPs may constitute a factor of susceptibility to disease.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, CD ; Antigens, Differentiation ; blood ; genetics ; CCAAT-Enhancer-Binding Protein-beta ; genetics ; CCAAT-Enhancer-Binding Proteins ; genetics ; CTLA-4 Antigen ; Exons ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; genetics ; immunology ; NFI Transcription Factors ; Point Mutation ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Promoter Regions, Genetic ; Thymoma ; genetics ; Thymus Hyperplasia ; genetics ; Thymus Neoplasms ; genetics ; Transcription Factors ; genetics
7.Identification and validation of novel C/EBPbeta-regulated genes in preadipocyte proliferation.
Chinese Medical Journal 2010;123(9):1190-1194
BACKGROUNDCCAAT/enhancer-binding protein beta (C/EBPbeta) is required for mitotic clonal expansion (MCE) during adipogenesis. It is still unclear how C/EBPbeta regulates MCE in the earlier differentiation programs of 3T3-L1 preadipocytes. The purpose of this paper was to understand why C/EBPbeta is required for preadipocyte proliferation, and identify new target genes of C/EBPbeta with chromatin immunoprecipitation (ChIP)-on-chip.
METHODSPostconfluent growth-arrested 3T3-L1 preadipocytes were induced to differentiation using a standard differentiation protocol. ChIP was performed at 20 hours after induction with specific anti-C/EBPbeta antibodies. The precipitated DNA was amplified, labeled and hybridized with a mouse promoter microarray. Compared with the control in which the ChIP experiment was performed with non-specific antibody, only the genes with a signal increasing more than 2 fold were considered as candidate genes.
RESULTSA total of 110 candidate genes were identified. BTG3 associated nuclear protein (SMAR1, Banp) and tripartite motif-containing 35 (Hls5, trim35) were two target genes among the 110 candidate genes which are involved in cell cycle regulation; the binding of C/EBPbeta to the promoter of banp and trim35 was verified by ChIP-PCR.
CONCLUSIONC/EBPbeta may regulate preadipocyte proliferation through activation of banp and trim35.
3T3-L1 Cells ; Adipocytes ; cytology ; Animals ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; CCAAT-Enhancer-Binding Protein-beta ; genetics ; metabolism ; Cell Cycle Proteins ; genetics ; metabolism ; Cell Differentiation ; genetics ; physiology ; Cell Proliferation ; Chromatin Immunoprecipitation ; DNA-Binding Proteins ; genetics ; metabolism ; Mice ; Nuclear Proteins ; genetics ; metabolism ; Oligonucleotide Array Sequence Analysis ; Polymerase Chain Reaction ; Protein Binding
8.Proinflammatory Effects of High Mobility Group B1 (HMGB1) Versus LPS and the Mechanism of IL-8 Promoter Stimulation by HMGB1.
Eun Ju JEON ; Hee Won KWAK ; Ju Han SONG ; Young Woo LEE ; Jae Woo CHUNG ; Jae Chul CHOI ; Jong Wook SHIN ; In Won PARK ; Byoung Whui CHOI ; Jae Yeol KIM
Tuberculosis and Respiratory Diseases 2007;62(4):299-307
BACKGROUND: High mobility group box 1 (HMGB1) is a novel, late mediator of inflammation. This study compared the pro-inflammatory effects of LPS and HMGB1. The transcriptional factors that play an important role in mediating the HMGB1-induced stimulation of IL-8 were also evaluated. METHODS: RAW264.7 cells were stimulated with either LPS (100 ng/ml) or HMGB1 (500 ng/ml). The TNF-alpha, MIP-2 and IL-1beta levels in the supernatant were evaluated by ELISA at 0, 2, 4, 8, 12 and 24h after stimulation. An acute lung injury was induced by an injection of LPS (5 mg/kg) or HMGB1 (2.5 mg/kg) into the peritoneum of the Balb/c mice. The lung cytokines and MPO activity were measured at 4h (for LPS) or 24h (for HMGB1) after the injection. The transcriptional factor binding sites for NF-IL6, NF-kappaB and AP-1 in the IL-8 promoter region were artificially mutated. Each mutant was ligated with pIL-6luc and transfected into the RAW264.7 cells. One hour after stimulation with HMGB1 (500 ng/ml), the cell lysate was analyzed for the luciferase activity. RESULTS: The expression of MIP-2, which peaked at 8h with LPS stimulation, increased sequentially until 24h after HMGB1 stimulation. An intraperitoneal injection of HMGB1, which induced a minimal increased in IL-1beta expression, provoked the accumulation of neutrophils the lung. A mutation of AP-1 as well as NF-kappaB in the IL-8 promoter region resulted in a lower luciferase activity after HMGB1 stimulation. CONCLUSION: The proinflammatory effects of HMGB1, particularly on IL-8, are mediated by both NF-kappaB and AP-1.
Acute Lung Injury
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Animals
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Binding Sites
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CCAAT-Enhancer-Binding Protein-beta
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Cytokines
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Enzyme-Linked Immunosorbent Assay
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HMGB1 Protein*
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Inflammation
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Injections, Intraperitoneal
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Interleukin-8*
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Luciferases
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Lung
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Mice
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Negotiating
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Neutrophils
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NF-kappa B
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Peritoneum
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Promoter Regions, Genetic
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Transcription Factor AP-1
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Tumor Necrosis Factor-alpha
9.Expressions of inflammatory and fibrogenic factors in perinephric and subcutaneous adipose tissues of patients with adrenocorticotropic hormone-independent Cushing's syndrome.
Chun-Yan WU ; Hui-Jian ZHANG ; Cun-Xia FAN ; Peng WU ; Qiang WEI ; Ying-Ying CAI ; Shao-Zhou ZOU ; Ling WANG ; Yao-Ming XUE ; Mei-Ping GUAN
Journal of Southern Medical University 2016;37(4):563-566
OBJECTIVETo investigate the expressions of inflammation- and fibrosis-related genes in perinephric and subcutaneous adipose tissues in patients with adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome.
METHODSThe perinephric and subcutaneous adipose tissues adipose tissues were obtained from 8 patients with ACTH-independent Cushing's syndrome undergoing laparoscopic retroperitoneal adrenalectomy. Real-time PCR was used to detect the mRNA expression levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), matrix metallopeptidase 2 (MMP-2), TIMP metallopeptidase inhibitor 1 (TIMP-1), early growth response 1 (EGR1), CCAAT/enhancer binding protein β(CEBPβ), uncoupling protein 1(UCP-1), PPARγ coactivator 1 alpha (PGC1α) and cell death-inducing DFFA-like effector a (CIDEA).
RESULTSThe mRNA level of CIDEA was significantly higher in the perinephric adipose tissue (peri-N) than in the subcutaneous adipose tissue (subQ) (P<0.05). The expressions of CEBPβ, UCP-1, and PGC1α mRNA in the peri-N were similar with those in the subQ. The expressions of IL-6, TIMP1 and EGR1 mRNA in the subQ were significantly higher than those in the peri-N (P<0.05). No significant difference in TNF-α and MMP-2 mRNA levels was found between peri-N and subQ.
CONCLUSIONThe expression levels of the inflammation- and fibrosis-related genes are higher in the subQ than in the peri-N of patients with ACTH-independent Cushing's syndrome, suggesting that chronic exposure to endogenous hypercortisolism may cause adipose tissue dysfunction.
Adrenalectomy ; Adrenocorticotropic Hormone ; CCAAT-Enhancer-Binding Protein-beta ; metabolism ; Cushing Syndrome ; metabolism ; surgery ; Early Growth Response Protein 1 ; metabolism ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; metabolism ; Real-Time Polymerase Chain Reaction ; Subcutaneous Fat ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; Uncoupling Protein 1 ; metabolism